/**
 * @license Highcharts JS v6.0.0 (2017-10-04)
 * Highcharts Drilldown module
 * 
 * Author: Torstein Honsi
 * License: www.highcharts.com/license
 *
 */
'use strict';
(function(factory) {
    if (typeof module === 'object' && module.exports) {
        module.exports = factory;
    } else {
        factory(Highcharts);
    }
}(function(Highcharts) {
    (function(H) {
        /**
         * Highcharts Drilldown module
         * 
         * Author: Torstein Honsi
         * License: www.highcharts.com/license
         *
         */


        var noop = H.noop,
            color = H.color,
            defaultOptions = H.defaultOptions,
            each = H.each,
            extend = H.extend,
            format = H.format,
            objectEach = H.objectEach,
            pick = H.pick,
            wrap = H.wrap,
            Chart = H.Chart,
            seriesTypes = H.seriesTypes,
            PieSeries = seriesTypes.pie,
            ColumnSeries = seriesTypes.column,
            Tick = H.Tick,
            fireEvent = H.fireEvent,
            inArray = H.inArray,
            ddSeriesId = 1;

        // Add language
        extend(defaultOptions.lang, {
            /**
             * The text for the button that appears when drilling down, linking
             * back to the parent series. The parent series' name is inserted for
             * `{series.name}`.
             * 
             * @type {String}
             * @default Back to {series.name}
             * @since 3.0.8
             * @product highcharts highmaps
             * @apioption lang.drillUpText
             */
            drillUpText: '◁ Back to {series.name}'
        });

        /**
         * Options for drill down, the concept of inspecting increasingly high 
         * resolution data through clicking on chart items like columns or pie slices.
         *
         * The drilldown feature requires the drilldown.js file to be loaded, 
         * found in the modules directory of the download package, or online at 
         * (code.highcharts.com/modules/drilldown.js)[code.highcharts.com/modules/drilldown.js].
         *
         * @type {Object}
         * @optionparent drilldown
         */
        defaultOptions.drilldown = {

            /**
             * When this option is false, clicking a single point will drill down
             * all points in the same category, equivalent to clicking the X axis
             * label.
             * 
             * @type {Boolean}
             * @sample {highcharts} highcharts/drilldown/allowpointdrilldown-false/
             *         Don't allow point drilldown
             * @default true
             * @since 4.1.7
             * @product highcharts
             * @apioption drilldown.allowPointDrilldown
             */



            /**
             * Set the animation for all drilldown animations. Animation of a drilldown
             * occurs when drilling between a column point and a column series,
             * or a pie slice and a full pie series. Drilldown can still be used
             * between series and points of different types, but animation will
             * not occur.
             * 
             * The animation can either be set as a boolean or a configuration
             * object. If `true`, it will use the 'swing' jQuery easing and a duration
             * of 500 ms. If used as a configuration object, the following properties
             * are supported:
             * 
             * <dl>
             * 
             * <dt>duration</dt>
             * 
             * <dd>The duration of the animation in milliseconds.</dd>
             * 
             * <dt>easing</dt>
             * 
             * <dd>A string reference to an easing function set on the `Math` object.
             * See [the easing demo](http://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/highcharts/plotoptions/series-
             * animation-easing/).</dd>
             * 
             * </dl>
             * 
             * @type {Boolean|Object}
             * @since 3.0.8
             * @product highcharts highmaps
             */
            animation: {

                /**
                 * Duration for the drilldown animation.
                 * @default 500
                 */
                duration: 500
            },

            /**
             * Options for the drill up button that appears when drilling down
             * on a series. The text for the button is defined in [lang.drillUpText](#lang.
             * drillUpText).
             * 
             * @type {Object}
             * @sample {highcharts} highcharts/drilldown/drillupbutton/ Drill up button
             * @sample {highmaps} highcharts/drilldown/drillupbutton/ Drill up button
             * @since 3.0.8
             * @product highcharts highmaps
             */
            drillUpButton: {

                /**
                 * Positioning options for the button within the `relativeTo` box.
                 * Available properties are `x`, `y`, `align` and `verticalAlign`.
                 * 
                 * @type {Object}
                 * @since 3.0.8
                 * @product highcharts highmaps
                 */
                position: {

                    /**
                     * Horizontal alignment.
                     * @type {String}
                     */
                    align: 'right',

                    /**
                     * The X offset of the button.
                     * @type {Number}
                     */
                    x: -10,

                    /**
                     * The Y offset of the button.
                     * @type {Number}
                     */
                    y: 10

                    /**
                     * Vertical alignment of the button.
                     *
                     * @type {String}
                     * @default top
                     * @validvalue ["top", "middle", "bottom"]
                     * @product highcharts highmaps
                     * @apioption drilldown.drillUpButton.position.verticalAlign
                     */
                }
                /**
                 * What box to align the button to. Can be either `plotBox` or
                 * `spacingBox.
                 * 
                 * @type {String}
                 * @default plotBox
                 * @validvalue ["plotBox", "spacingBox"]
                 * @since 3.0.8
                 * @product highcharts highmaps
                 * @apioption drilldown.drillUpButton.relativeTo
                 */

                /**
                 * A collection of attributes for the button. The object takes SVG attributes
                 * like `fill`, `stroke`, `stroke-width` or `r`, the border radius.
                 * The theme also supports `style`, a collection of CSS properties for
                 * the text. Equivalent attributes for the hover state are given in
                 * `theme.states.hover`.
                 * 
                 * @type {Object}
                 * @see In styled mode, drill-up button styles can be applied with the
                 * `.highcharts-drillup-button` class.
                 * @sample {highcharts} highcharts/drilldown/drillupbutton/
                 *         Button theming
                 * @sample {highmaps} highcharts/drilldown/drillupbutton/
                 *         Button theming
                 * @since 3.0.8
                 * @product highcharts highmaps
                 * @apioption drilldown.drillUpButton.theme
                 */
            }

            /**
             * An array of series configurations for the drill down. Each series
             * configuration uses the same syntax as the [series](#series) option
             * set. These drilldown series are hidden by default. The drilldown
             * series is linked to the parent series' point by its `id`.
             * 
             * @type {Array<Object>}
             * @since 3.0.8
             * @product highcharts highmaps
             * @apioption drilldown.series
             */
        };



        /**
         * Fires when a drilldown point is clicked, before the new series is
         * added. This event is also utilized for async drilldown, where the
         * seriesOptions are not added by option, but rather loaded async. Note
         * that when clicking a category label to trigger multiple series drilldown,
         * one `drilldown` event is triggered per point in the category.
         * 
         * Event arguments:
         * 
         * <dl>
         * 
         * <dt>`category`</dt>
         * 
         * <dd>If a category label was clicked, which index.</dd>
         * 
         * <dt>`point`</dt>
         * 
         * <dd>The originating point.</dd>
         * 
         * <dt>`originalEvent`</dt>
         * 
         * <dd>The original browser event (usually click) that triggered the
         * drilldown.</dd>
         * 
         * <dt>`points`</dt>
         * 
         * <dd>If a category label was clicked, this array holds all points
         * corresponing to the category.</dd>
         * 
         * <dt>`seriesOptions`</dt>
         * 
         * <dd>Options for the new series</dd>
         * 
         * </dl>
         * 
         * @type {Function}
         * @context Chart
         * @sample {highcharts} highcharts/drilldown/async/ Async drilldown
         * @since 3.0.8
         * @product highcharts highmaps
         * @apioption chart.events.drilldown
         */

        /**
         * Fires when drilling up from a drilldown series.
         * 
         * @type {Function}
         * @context Chart
         * @since 3.0.8
         * @product highcharts highmaps
         * @apioption chart.events.drillup
         */

        /**
         * In a chart with multiple drilldown series, this event fires after
         * all the series have been drilled up.
         * 
         * @type {Function}
         * @context Chart
         * @since 4.2.4
         * @product highcharts highmaps
         * @apioption chart.events.drillupall
         */

        /**
         * The `id` of a series in the [drilldown.series](#drilldown.series)
         * array to use for a drilldown for this point.
         * 
         * @type {String}
         * @sample {highcharts} highcharts/drilldown/basic/ Basic drilldown
         * @since 3.0.8
         * @product highcharts
         * @apioption series.line.data.drilldown
         */

        /**
         * A general fadeIn method
         */
        H.SVGRenderer.prototype.Element.prototype.fadeIn = function(animation) {
            this
                .attr({
                    opacity: 0.1,
                    visibility: 'inherit'
                })
                .animate({
                    opacity: pick(this.newOpacity, 1) // newOpacity used in maps
                }, animation || {
                    duration: 250
                });
        };

        /**
         * Add a series to the chart as drilldown from a specific point in the parent
         * series. This method is used for async drilldown, when clicking a point in a
         * series should result in loading and displaying a more high-resolution series.
         * When not async, the setup is simpler using the {@link 
         * https://api.highcharts.com/highcharts/drilldown.series|drilldown.series}
         * options structure.
         *
         * @memberOf Highcharts.Chart
         * @function #addSeriesAsDrilldown
         * 
         * @param  {Highcharts.Point} point
         *         The point from which the drilldown will start.
         * @param  {SeriesOptions} options
         *         The series options for the new, detailed series.
         *
         * @sample highcharts/drilldown/async/ Async drilldown
         */
        Chart.prototype.addSeriesAsDrilldown = function(point, options) {
            this.addSingleSeriesAsDrilldown(point, options);
            this.applyDrilldown();
        };
        Chart.prototype.addSingleSeriesAsDrilldown = function(point, ddOptions) {
            var oldSeries = point.series,
                xAxis = oldSeries.xAxis,
                yAxis = oldSeries.yAxis,
                newSeries,
                pointIndex,
                levelSeries = [],
                levelSeriesOptions = [],
                level,
                levelNumber,
                last,
                colorProp;



            colorProp = {
                colorIndex: pick(point.colorIndex, oldSeries.colorIndex)
            };


            if (!this.drilldownLevels) {
                this.drilldownLevels = [];
            }

            levelNumber = oldSeries.options._levelNumber || 0;

            // See if we can reuse the registered series from last run
            last = this.drilldownLevels[this.drilldownLevels.length - 1];
            if (last && last.levelNumber !== levelNumber) {
                last = undefined;
            }

            ddOptions = extend(extend({
                _ddSeriesId: ddSeriesId++
            }, colorProp), ddOptions);
            pointIndex = inArray(point, oldSeries.points);

            // Record options for all current series
            each(oldSeries.chart.series, function(series) {
                if (series.xAxis === xAxis && !series.isDrilling) {
                    series.options._ddSeriesId = series.options._ddSeriesId || ddSeriesId++;
                    series.options._colorIndex = series.userOptions._colorIndex;
                    series.options._levelNumber = series.options._levelNumber || levelNumber; // #3182

                    if (last) {
                        levelSeries = last.levelSeries;
                        levelSeriesOptions = last.levelSeriesOptions;
                    } else {
                        levelSeries.push(series);
                        levelSeriesOptions.push(series.options);
                    }
                }
            });

            // Add a record of properties for each drilldown level
            level = extend({
                levelNumber: levelNumber,
                seriesOptions: oldSeries.options,
                levelSeriesOptions: levelSeriesOptions,
                levelSeries: levelSeries,
                shapeArgs: point.shapeArgs,
                bBox: point.graphic ? point.graphic.getBBox() : {}, // no graphic in line series with markers disabled
                color: point.isNull ? new H.Color(color).setOpacity(0).get() : color,
                lowerSeriesOptions: ddOptions,
                pointOptions: oldSeries.options.data[pointIndex],
                pointIndex: pointIndex,
                oldExtremes: {
                    xMin: xAxis && xAxis.userMin,
                    xMax: xAxis && xAxis.userMax,
                    yMin: yAxis && yAxis.userMin,
                    yMax: yAxis && yAxis.userMax
                }
            }, colorProp);

            // Push it to the lookup array
            this.drilldownLevels.push(level);

            // Reset names to prevent extending (#6704)
            if (xAxis && xAxis.names) {
                xAxis.names.length = 0;
            }

            newSeries = level.lowerSeries = this.addSeries(ddOptions, false);
            newSeries.options._levelNumber = levelNumber + 1;
            if (xAxis) {
                xAxis.oldPos = xAxis.pos;
                xAxis.userMin = xAxis.userMax = null;
                yAxis.userMin = yAxis.userMax = null;
            }

            // Run fancy cross-animation on supported and equal types
            if (oldSeries.type === newSeries.type) {
                newSeries.animate = newSeries.animateDrilldown || noop;
                newSeries.options.animation = true;
            }
        };

        Chart.prototype.applyDrilldown = function() {
            var drilldownLevels = this.drilldownLevels,
                levelToRemove;

            if (drilldownLevels && drilldownLevels.length > 0) { // #3352, async loading
                levelToRemove = drilldownLevels[drilldownLevels.length - 1].levelNumber;
                each(this.drilldownLevels, function(level) {
                    if (level.levelNumber === levelToRemove) {
                        each(level.levelSeries, function(series) {
                            if (series.options && series.options._levelNumber === levelToRemove) { // Not removed, not added as part of a multi-series drilldown
                                series.remove(false);
                            }
                        });
                    }
                });
            }
            this.pointer.reset();
            this.redraw();
            this.showDrillUpButton();
        };

        Chart.prototype.getDrilldownBackText = function() {
            var drilldownLevels = this.drilldownLevels,
                lastLevel;
            if (drilldownLevels && drilldownLevels.length > 0) { // #3352, async loading
                lastLevel = drilldownLevels[drilldownLevels.length - 1];
                lastLevel.series = lastLevel.seriesOptions;
                return format(this.options.lang.drillUpText, lastLevel);
            }

        };

        Chart.prototype.showDrillUpButton = function() {
            var chart = this,
                backText = this.getDrilldownBackText(),
                buttonOptions = chart.options.drilldown.drillUpButton,
                attr,
                states;


            if (!this.drillUpButton) {
                attr = buttonOptions.theme;
                states = attr && attr.states;

                this.drillUpButton = this.renderer.button(
                        backText,
                        null,
                        null,
                        function() {
                            chart.drillUp();
                        },
                        attr,
                        states && states.hover,
                        states && states.select
                    )
                    .addClass('highcharts-drillup-button')
                    .attr({
                        align: buttonOptions.position.align,
                        zIndex: 7
                    })
                    .add()
                    .align(buttonOptions.position, false, buttonOptions.relativeTo || 'plotBox');
            } else {
                this.drillUpButton.attr({
                        text: backText
                    })
                    .align();
            }
        };

        /**
         * When the chart is drilled down to a child series, calling `chart.drillUp()`
         * will drill up to the parent series. Requires the drilldown module.
         *
         * @function drillUp
         * @memberOf Highcharts.Chart
         */
        Chart.prototype.drillUp = function() {
            var chart = this,
                drilldownLevels = chart.drilldownLevels,
                levelNumber = drilldownLevels[drilldownLevels.length - 1].levelNumber,
                i = drilldownLevels.length,
                chartSeries = chart.series,
                seriesI,
                level,
                oldSeries,
                newSeries,
                oldExtremes,
                addSeries = function(seriesOptions) {
                    var addedSeries;
                    each(chartSeries, function(series) {
                        if (series.options._ddSeriesId === seriesOptions._ddSeriesId) {
                            addedSeries = series;
                        }
                    });

                    addedSeries = addedSeries || chart.addSeries(seriesOptions, false);
                    if (addedSeries.type === oldSeries.type && addedSeries.animateDrillupTo) {
                        addedSeries.animate = addedSeries.animateDrillupTo;
                    }
                    if (seriesOptions === level.seriesOptions) {
                        newSeries = addedSeries;
                    }
                };

            while (i--) {

                level = drilldownLevels[i];
                if (level.levelNumber === levelNumber) {
                    drilldownLevels.pop();

                    // Get the lower series by reference or id
                    oldSeries = level.lowerSeries;
                    if (!oldSeries.chart) { // #2786
                        seriesI = chartSeries.length; // #2919
                        while (seriesI--) {
                            if (chartSeries[seriesI].options.id === level.lowerSeriesOptions.id &&
                                chartSeries[seriesI].options._levelNumber === levelNumber + 1) { // #3867
                                oldSeries = chartSeries[seriesI];
                                break;
                            }
                        }
                    }
                    oldSeries.xData = []; // Overcome problems with minRange (#2898)

                    each(level.levelSeriesOptions, addSeries);

                    fireEvent(chart, 'drillup', {
                        seriesOptions: level.seriesOptions
                    });

                    if (newSeries.type === oldSeries.type) {
                        newSeries.drilldownLevel = level;
                        newSeries.options.animation = chart.options.drilldown.animation;

                        if (oldSeries.animateDrillupFrom && oldSeries.chart) { // #2919
                            oldSeries.animateDrillupFrom(level);
                        }
                    }
                    newSeries.options._levelNumber = levelNumber;

                    oldSeries.remove(false);

                    // Reset the zoom level of the upper series
                    if (newSeries.xAxis) {
                        oldExtremes = level.oldExtremes;
                        newSeries.xAxis.setExtremes(oldExtremes.xMin, oldExtremes.xMax, false);
                        newSeries.yAxis.setExtremes(oldExtremes.yMin, oldExtremes.yMax, false);
                    }
                }
            }

            // Fire a once-off event after all series have been drilled up (#5158)
            fireEvent(chart, 'drillupall');

            this.redraw();

            if (this.drilldownLevels.length === 0) {
                this.drillUpButton = this.drillUpButton.destroy();
            } else {
                this.drillUpButton.attr({
                        text: this.getDrilldownBackText()
                    })
                    .align();
            }

            this.ddDupes.length = []; // #3315
        };


        /**
         * When drilling up, keep the upper series invisible until the lower series has
         * moved into place
         */
        ColumnSeries.prototype.animateDrillupTo = function(init) {
            if (!init) {
                var newSeries = this,
                    level = newSeries.drilldownLevel;

                // First hide all items before animating in again
                each(this.points, function(point) {
                    var dataLabel = point.dataLabel;

                    if (point.graphic) { // #3407
                        point.graphic.hide();
                    }

                    if (dataLabel) {
                        // The data label is initially hidden, make sure it is not faded
                        // in (#6127)
                        dataLabel.hidden = dataLabel.attr('visibility') === 'hidden';

                        if (!dataLabel.hidden) {
                            dataLabel.hide();
                            if (point.connector) {
                                point.connector.hide();
                            }
                        }
                    }
                });


                // Do dummy animation on first point to get to complete
                setTimeout(function() {
                    if (newSeries.points) { // May be destroyed in the meantime, #3389
                        each(newSeries.points, function(point, i) {
                            // Fade in other points			  
                            var verb =
                                i === (level && level.pointIndex) ? 'show' : 'fadeIn',
                                inherit = verb === 'show' ? true : undefined,
                                dataLabel = point.dataLabel;


                            if (point.graphic) { // #3407
                                point.graphic[verb](inherit);
                            }

                            if (dataLabel && !dataLabel.hidden) { // #6127
                                dataLabel[verb](inherit);
                                if (point.connector) {
                                    point.connector[verb](inherit);
                                }
                            }
                        });
                    }
                }, Math.max(this.chart.options.drilldown.animation.duration - 50, 0));

                // Reset
                this.animate = noop;
            }

        };

        ColumnSeries.prototype.animateDrilldown = function(init) {
            var series = this,
                drilldownLevels = this.chart.drilldownLevels,
                animateFrom,
                animationOptions = this.chart.options.drilldown.animation,
                xAxis = this.xAxis;

            if (!init) {
                each(drilldownLevels, function(level) {
                    if (series.options._ddSeriesId === level.lowerSeriesOptions._ddSeriesId) {
                        animateFrom = level.shapeArgs;

                    }
                });

                animateFrom.x += (pick(xAxis.oldPos, xAxis.pos) - xAxis.pos);

                each(this.points, function(point) {
                    var animateTo = point.shapeArgs;



                    if (point.graphic) {
                        point.graphic
                            .attr(animateFrom)
                            .animate(
                                extend(point.shapeArgs, {
                                    fill: point.color || series.color
                                }),
                                animationOptions
                            );
                    }
                    if (point.dataLabel) {
                        point.dataLabel.fadeIn(animationOptions);
                    }
                });
                this.animate = null;
            }

        };

        /**
         * When drilling up, pull out the individual point graphics from the lower series
         * and animate them into the origin point in the upper series.
         */
        ColumnSeries.prototype.animateDrillupFrom = function(level) {
            var animationOptions = this.chart.options.drilldown.animation,
                group = this.group,
                // For 3d column series all columns are added to one group 
                // so we should not delete the whole group. #5297
                removeGroup = group !== this.chart.columnGroup,
                series = this;

            // Cancel mouse events on the series group (#2787)
            each(series.trackerGroups, function(key) {
                if (series[key]) { // we don't always have dataLabelsGroup
                    series[key].on('mouseover');
                }
            });

            if (removeGroup) {
                delete this.group;
            }

            each(this.points, function(point) {
                var graphic = point.graphic,
                    animateTo = level.shapeArgs,
                    complete = function() {
                        graphic.destroy();
                        if (group && removeGroup) {
                            group = group.destroy();
                        }
                    };

                if (graphic) {

                    delete point.graphic;



                    if (animationOptions) {
                        graphic.animate(
                            animateTo,
                            H.merge(animationOptions, {
                                complete: complete
                            })
                        );
                    } else {
                        graphic.attr(animateTo);
                        complete();
                    }
                }
            });
        };

        if (PieSeries) {
            extend(PieSeries.prototype, {
                animateDrillupTo: ColumnSeries.prototype.animateDrillupTo,
                animateDrillupFrom: ColumnSeries.prototype.animateDrillupFrom,

                animateDrilldown: function(init) {
                    var level = this.chart.drilldownLevels[this.chart.drilldownLevels.length - 1],
                        animationOptions = this.chart.options.drilldown.animation,
                        animateFrom = level.shapeArgs,
                        start = animateFrom.start,
                        angle = animateFrom.end - start,
                        startAngle = angle / this.points.length;

                    if (!init) {
                        each(this.points, function(point, i) {
                            var animateTo = point.shapeArgs;



                            if (point.graphic) {
                                point.graphic
                                    .attr(H.merge(animateFrom, {
                                        start: start + i * startAngle,
                                        end: start + (i + 1) * startAngle
                                    }))[animationOptions ? 'animate' : 'attr'](
                                        animateTo,
                                        animationOptions
                                    );
                            }
                        });
                        this.animate = null;
                    }
                }
            });
        }

        H.Point.prototype.doDrilldown = function(_holdRedraw, category, originalEvent) {
            var series = this.series,
                chart = series.chart,
                drilldown = chart.options.drilldown,
                i = (drilldown.series || []).length,
                seriesOptions;

            if (!chart.ddDupes) {
                chart.ddDupes = [];
            }

            while (i-- && !seriesOptions) {
                if (drilldown.series[i].id === this.drilldown && inArray(this.drilldown, chart.ddDupes) === -1) {
                    seriesOptions = drilldown.series[i];
                    chart.ddDupes.push(this.drilldown);
                }
            }

            // Fire the event. If seriesOptions is undefined, the implementer can check for 
            // seriesOptions, and call addSeriesAsDrilldown async if necessary.
            fireEvent(chart, 'drilldown', {
                point: this,
                seriesOptions: seriesOptions,
                category: category,
                originalEvent: originalEvent,
                points: category !== undefined && this.series.xAxis.getDDPoints(category).slice(0)
            }, function(e) {
                var chart = e.point.series && e.point.series.chart,
                    seriesOptions = e.seriesOptions;
                if (chart && seriesOptions) {
                    if (_holdRedraw) {
                        chart.addSingleSeriesAsDrilldown(e.point, seriesOptions);
                    } else {
                        chart.addSeriesAsDrilldown(e.point, seriesOptions);
                    }
                }
            });


        };

        /**
         * Drill down to a given category. This is the same as clicking on an axis label.
         */
        H.Axis.prototype.drilldownCategory = function(x, e) {
            objectEach(this.getDDPoints(x), function(point) {
                if (point && point.series && point.series.visible && point.doDrilldown) { // #3197
                    point.doDrilldown(true, x, e);
                }
            });
            this.chart.applyDrilldown();
        };

        /**
         * Return drillable points for this specific X value
         */
        H.Axis.prototype.getDDPoints = function(x) {
            var ret = [];
            each(this.series, function(series) {
                var i,
                    xData = series.xData,
                    points = series.points;

                for (i = 0; i < xData.length; i++) {
                    if (xData[i] === x && series.options.data[i] && series.options.data[i].drilldown) {
                        ret.push(points ? points[i] : true);
                        break;
                    }
                }
            });
            return ret;
        };


        /**
         * Make a tick label drillable, or remove drilling on update
         */
        Tick.prototype.drillable = function() {
            var pos = this.pos,
                label = this.label,
                axis = this.axis,
                isDrillable = axis.coll === 'xAxis' && axis.getDDPoints,
                ddPointsX = isDrillable && axis.getDDPoints(pos);

            if (isDrillable) {
                if (label && ddPointsX.length) {
                    label.drillable = true;



                    label
                        .addClass('highcharts-drilldown-axis-label')

                        .on('click', function(e) {
                            axis.drilldownCategory(pos, e);
                        });

                } else if (label && label.drillable) {



                    label.on('click', null); // #3806			
                    label.removeClass('highcharts-drilldown-axis-label');
                }
            }
        };

        /**
         * Always keep the drillability updated (#3951)
         */
        wrap(Tick.prototype, 'addLabel', function(proceed) {
            proceed.call(this);
            this.drillable();
        });


        /**
         * On initialization of each point, identify its label and make it clickable. Also, provide a
         * list of points associated to that label.
         */
        wrap(H.Point.prototype, 'init', function(proceed, series, options, x) {
            var point = proceed.call(this, series, options, x),
                xAxis = series.xAxis,
                tick = xAxis && xAxis.ticks[x];

            if (point.drilldown) {

                // Add the click event to the point 
                H.addEvent(point, 'click', function(e) {
                    if (series.xAxis && series.chart.options.drilldown.allowPointDrilldown === false) {
                        series.xAxis.drilldownCategory(point.x, e); // #5822, x changed
                    } else {
                        point.doDrilldown(undefined, undefined, e);
                    }
                });
                /*
                wrap(point, 'importEvents', function (proceed) { // wrapping importEvents makes point.click event work
                	if (!this.hasImportedEvents) {
                		proceed.call(this);
                		H.addEvent(this, 'click', function () {
                			this.doDrilldown();
                		});
                	}
                });
                */

            }

            // Add or remove click handler and style on the tick label
            if (tick) {
                tick.drillable();
            }

            return point;
        });

        wrap(H.Series.prototype, 'drawDataLabels', function(proceed) {
            var css = this.chart.options.drilldown.activeDataLabelStyle,
                renderer = this.chart.renderer;

            proceed.call(this);

            each(this.points, function(point) {
                var dataLabelsOptions = point.options.dataLabels,
                    pointCSS = pick(
                        point.dlOptions,
                        dataLabelsOptions && dataLabelsOptions.style, {}
                    );

                if (point.drilldown && point.dataLabel) {
                    if (css.color === 'contrast') {
                        pointCSS.color = renderer.getContrast(point.color || this.color);
                    }
                    if (dataLabelsOptions && dataLabelsOptions.color) {
                        pointCSS.color = dataLabelsOptions.color;
                    }
                    point.dataLabel
                        .addClass('highcharts-drilldown-data-label');


                }
            }, this);
        });


        var applyCursorCSS = function(element, cursor, addClass) {
            element[addClass ? 'addClass' : 'removeClass']('highcharts-drilldown-point');


        };

        // Mark the trackers with a pointer 
        var drawTrackerWrapper = function(proceed) {
            proceed.call(this);
            each(this.points, function(point) {
                if (point.drilldown && point.graphic) {
                    applyCursorCSS(point.graphic, 'pointer', true);
                }
            });
        };

        var setPointStateWrapper = function(proceed, state) {
            var ret = proceed.apply(this, Array.prototype.slice.call(arguments, 1));

            if (this.drilldown && this.series.halo && state === 'hover') {
                applyCursorCSS(this.series.halo, 'pointer', true);
            } else if (this.series.halo) {
                applyCursorCSS(this.series.halo, 'auto', false);
            }
            return ret;
        };


        objectEach(seriesTypes, function(seriesType) {
            wrap(seriesType.prototype, 'drawTracker', drawTrackerWrapper);
            wrap(seriesType.prototype.pointClass.prototype, 'setState', setPointStateWrapper);
        });

    }(Highcharts));
}));
